1. Field of the Invention
The present invention relates to the management of storage media used to store computer data, and more particularly, to a device and method for maximizing the efficiency and accuracy of the management of storage media containing backup data by the automated tracking and management of the storage media using media pools.
2. Description of the Prior Art
Today's computer data processing systems generally include a host processor having one or more central processing units. The host processor is supported by one or more memory facilities and input/output interfaces. The processing units execute instructions which specify the manipulation of data stored within the memory facilities.
The advent of high capacity memory facilities confined with the necessity for accurate and restorable data available for the host processor makes the cost and performance of computer memory backup critical to the operability of the computer. Backup or storage media management has traditionally been performed manually. The data manager decides when to migrate or backup data, and where and how such migrated and backed up files should be stored. Accordingly, the decisions involve not only what and how often to store data from the computer to the storage media but also how to manage the transfer of the data from the computer to the storage media. Such decisions also include how to organize the storage media most efficiently and accurately such that the backup data is available when a restoration is necessary. Such decisions are time consuming and transparent to the normal operations of the computer. Indeed, limitations in storage media management usually become apparent only after the discovery of a problem of reading memory from its primary source. At that point, resort to the backup system is required.
In recent years, computer software has been developed to automate storage management of such backup media using media rotation techniques. One known media rotation technique uses a weekly rotation. According to this technique, seven backup media are used, that is, each individual media is assigned one for each day of the week. On a given day (e.g, a Monday), the backup media for Monday is used. Thus, each backup media gets reused on its assigned day during successive weeks. This is a simple rotation technique; however, it has the disadvantage of not being able to save data for more than seven days.
Another known technique is "Grandfather-Father-Son" or GFS. The GFS technique is often not practical because it requires the user to keep many backup media, which may become unmanageable. Also, a GFS rotation is fixed so that users cannot set up their own rotation parameters.
The "Tower of Hanoi" is another known rotation technique which utilizes the backup media differently than GFS. However, this technique stores incremental and full backups on many different backup media. Thus, during a restore process, the user may be required to use several different backup media to restore the desired data. Under the Tower of Hanoi approach, it is difficult to manage the backup media.
Further, it is well known to combine two or more backup storage media, for example, tapes, together in what are referred to as media pools. However, the pools are usually manually labeled and managed according to a user's individual handling system. Such manual operations reduce the efficiency selecting backup media and increase a likelihood that a media containing currently needed backup data will be inadvertently overwritten.
In addition, previous storage management devices handle each media within a media pool as a single unit of storage rather than organizing and monitoring individual portions of the media which may be available for additional storage. This approach prevents efficient use of each portion of the media as well as efficient use of the media in its entirety. This results in the quantity of storage media being needlessly high which places more strain on the system and the persons managing the system.
In view of the foregoing considerations, there is a need for an improved system which automates the organization and handling of backup media, and in particular, tapes.